The attention paid to negotiated decision making in environmental legislations calls for the development of new tools to help the negotiation. These tools are generally based on Game Theory which offers precise concepts of equilibrium. However, numerous questions remain open. Namely, what impact the formation of coalitions has on the negotiated agreement is such an open question the paper tries to deal with.

Using an existing integrated assessment model, based on an optimal control formalism we compare different methods for introducing intergenerational equity in cost benefit analysis. We compare, in particular, the transient trajectories when one uses (i) a zero pure time preference rate, (ii) an hyperbolic rate and (iii) an intergenerational equilibrium solution. We discuss the implications for the evaluation of long term environmental and sustainable development policies.

We propose in this research to model an emission control situation using the joint implementation mechanism (JI). A differential game composed of two non-identical players is proposed. Three scenarios are studied; the business-as-usual scenario and two scenarios under the agreement, an autarcy scenario and a joint implementation scenario. This paper contributes to determining the conditions under which the JI is attractive.

The aim of this paper is to provide a game-theoretic interpretation of joint implementation in environmental projects and to assess the merit of such a strategy. We consider a two-player game and solve it under three different modes of play. In the first case, the countries play a non cooperative game and optimize their profits under an environmental constraint without having access to joint implementation. In the second case, we relax the last restriction to assess the merit of joint implementation by comparing the players' profits achieved in the two cases. In the last scenario, the players jointly optimize their profits under a collective environmental constraint. Comparing the last scenario's welfares to the previous one permits to assess the merit of cooperation which is here an extreme case of a bubble system in the sense that the players also maximize jointly their performance indexes.